To exclude possible artifacts due to transfection, a stable ARP2-knockdown A549 cell line (ARP2/KD-A549 cells) was generated using a lentiviral vector system expressing three small hairpin RNAs to ARP2, and RSV-GFP infection was analyzed at 6 or 12 hpi by flow cytometry using GFP expression as a marker for infection. The gene discussed is ACTR2; the disease is infection.